The permafrost from Yukon in Canada, which contains DNA from past environments dating back to at least 30,000 years old, shows that woolly mammals roamed this region up until 5,000 years ago.
McMaster University scientists made the discovery, building on previous research which suggested that the large animals had died 9700 years ago during the mid-Holocene period – an era of climate instability.
The soil samples from Canada’s Yukon Klondike were collected in the first decade of 2010. They were then placed in a freeze and left behind.
Gizmodo was told by Tyler Murchie (an archaeologist who studies ancient DNA) that he noticed the samples.

The ancient DNA from past environments, dating back to Yukon (Canada), shows woolly mammoths lived in the area as recent as 5,000 year ago. McMaster University scientists made the discovery, building on previous research which suggested that the huge animals had died 9700 years ago during the mid-Holocene period.
Murchie and his colleagues isolated the DNA and rebuilt it. It shows how the genetic material of animals and plants changed during Pleistocene to Holocene transition. The unstable climatic period was 11,000 to 14,000 years ago, when large species like mammoths and mastodons disappeared.
Analyses also revealed that Yukon horses and mammoths were disappearing before climate change.
However, the researchers note that they did not go extinct due to humans overhunting them as previously thought.
Both the woolly mammoths and the horse ancient survived up to 5,000 years ago. That brought them into the mid Holocene, which is roughly the 11,000 year interval that we now live in.

The soil samples from Canada’s Yukon Klondike were collected in the first decade of 2010. They were then placed in a freeze and left behind.
The changing climate in Yukon caused dramatic changes to the Yukon’s environment during the Holocene.
It was previously flowing with lush grasslands, known as the ‘Mammoth Steppe’, but became overrun with shrubs and mosses that were not seen as food for large grazing herds of mammoths, horses and bison.
Experts say the grasslands can’t survive in this part of North America because they don’t have enough large grazing animals.
Hendrik Poinar is the lead author and director at the McMaster Ancient DNA Centre. He said that this rich data gives a rare window into the megafuana population dynamics. It also nuances the debate around the topic of their extinction by more subtle reconstructions from past ecosystems.
McMaster scientists were able to better date the extinction of the ancient animals with the help of new technology that was not available when they proposed the creatures were living in the Yukon 9,700 years ago.
Murchie stated, “Now that these technologies are available, we can see how many life-history data is stored in permafrost.”

Murchie and his colleagues isolated the DNA and rebuilt it. This shows the fluctuations in animal and plant communities during the Pleistocene to Holocene transition. It was an unstable climate period between 11,000 and 14,000 years ago, when large species like mammoths and mastodons disappeared.
He said that the permafrost’s genetic data is “very large” and allows for an ecosystem- and evolutionary reconstruction scale unmatched by other methods.
Ross MacPhee, American Museum of Natural History co-author, stated that although mammoths have been extinct for all time, horses remain.
The horse species Equus caballus is closely related to that of the Yukon’s horse 5,000 year ago.
“Biologically this means that the horse is a North American native mammal and should therefore be treated accordingly.”